• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.39-48
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• 2009

Previous studies on the effects of speaking rate on voice onset time (VOT) of stops in English, French, Icelandic, and Thai indicate that speaking rate asymmetrically affects VOT values. That is, pre-voiced and long-lag stops vary due to the rate factor more than short-lag stops do. One suggested explanation for this asymmetry is that it is due to the necessity of maintaining phonetic contrasts among the stop categories. Since pre-voiced and long-lag stops represent the ends of the VOT scale, they encompass broad swathes of that range and consequently allow for large variations. On the other hand, the VOT variations of short-lag stops may result in overlap with the VOTs of long-lag stops. This study aimed to explore the effects of speaking rate on the VOTs of Korean stops and see whether Korean fortis and lenis stops are limited in the degrees of variation as a function of rates due to the existence of stops with larger VOT values, lenis and aspirated stops respectively. Conversely, aspirated stops were expected to show more variation since there are no other categories with longer VOTs. Fortis, lenis, and aspirated stops in /CVn/ words (C = bilabial or velar stop, V = /i/ or /a/) were examined in isolation, and at normal and fast rates in a carrier sentence. Speaking rates were controlled by alternating words or sentences on a computer screen at intervals of two seconds for the isolation- and normal-rate conditions and one second for the fast-rate condition. This study found that while the VOTs of fortis stops did not change significantly, those of lenis and aspirated stops showed considerable changes as a function of speaking rates. Also, overlap between lenis and aspirated stops occurred considerably at all speaking rates. These phenomena were interpreted to relate to the fact that VOT contrasts between lenis and aspirated stops in Korean are currently being collapsed. Large variations of lenis stops as a function of rates seem to occur due to a weak motivation to limit the degree of variations for the purpose of maintaining phonetic contrasts. The significant overlap between lenis and aspirated stops at all rates was interpreted to occur because the VOT merger between the two categories became considerably fixed. Also the percentage of correctly-classified VOTs by optimal-boundary values between lenis and aspirated stops turned out to be lower than in previously-studied languages. This was interpreted to be further evidence that VOTs are losing their role in contrasting the two stop categories in Korean.

• Archives of Plastic Surgery
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• v.47 no.2
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• pp.126-134
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• 2020

Background Pectus excavatum is less common in females than in males, and it often aggravates a coexistent breast asymmetry. We conducted a study comparing female patients' versus medical professionals' evaluation of pectus excavatum repair to assess differences in aesthetic outcome ratings. Moreover, we evaluated the influence of surgical correction on patients' self-perception. Methods Of 30 female patients who were initially screened, 18 patients (mean age, 20 years) who underwent bar removal after surgical correction of pectus excavatum deformity participated in the survey (60%). They completed a questionnaire rating their appearance before and after surgery and responded to a psychological questionnaire about the changes that they had experienced. The mean interval between pectus bar removal and evaluation was 28 months. Standardized preoperative and postoperative patient photographs were evaluated using the same questionnaire by a panel of medical professionals and students (n=24) and the results were compared. Results Patients rated their preoperative deformity as more severe than the other evaluators, revealing the significant impact of the deformity on patients' self-perception. Postoperatively, patient and professional evaluations were much better than before and were very similar. The psychological evaluation showed a clear improvement in well-being. The ratings of the medical professionals were not influenced by their degree of medical education. Conclusions Surgical correction of pectus excavatum in female patients positively influences body perception and psychological well-being. It should therefore not be considered as a merely aesthetic correction, but as an important procedure to restore a patient's self-perception.

• Journal of the Korean Magnetics Society
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• v.22 no.1
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• pp.15-18
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• 2012

The olivine structured $LiFe_{0.9}Mn_{0.1}PO_4$ material was prepared by solid state method, and was analyzed by x-ray diffractometer (XRD), superconducting quantum interference devices (SQUID) and Mossbauer spectroscopy. The crystal structure of $LiFe_{0.9}Mn_{0.1}PO_4$ was determined to be orthorhombic (space group: Pnma) by Rietveld refinement method. The value of N$\acute{e}$el temperature ($T_N$) for $LiFe_{0.9}Mn_{0.1}PO_4$ was determined 50 K. The temperature dependence of the magnetization curves showed magnetic phase transition from paramagnetic to antiferromagnetic at $T_N$ by SQUID measurement. M$\ddot{o}$ssbauer spectra of $LiFe_{0.9}Mn_{0.1}PO_4$ showed 2 absorption lines at temperatures above $T_N$ and showed asymmetric 8 absorption lines at temperatures below $T_N$. These spectra occurred due to the magnetic dipole and electric quardrupole interaction caused by strong crystalline field at asymmetric $FeO_6$ octahedral sites.

• Annual Conference on Human and Language Technology
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• 1999.10e
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• pp.359-367
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• 1999

형태소를 공유하고 있는 어휘가 심성 어휘집(mental lexicon)에 어떻게 저장되어 있고 어떻게 어휘 접근되는지에 관하여 여러 설명이 제기되었다 첫 번째 가설은 형태소 공유 어휘는 심성 어휘집에 모두 같은 어근 혹은 어간을 중심으로 저장되어 있다는 것이다. 두 번째 가설은 어간이나 어근으로의 분석을 통해 활용된 단어를 이해하는 것이 아니라 일단 활용된 형태의 어휘를 심성 어휘집에서 찾고, 만일 해당되는 것이 발견되면, 그 활용된 어절의 이해가 끝나게 되고, 만일에 해당되는 것이 심성 어휘집에 존재하지 않는 경우에만 부수적인 과정으로 구성 형태소로의 분석이 이루어진다는 것이다. 세 번째 가설은 어휘의 품사, 어휘의 빈도, 형태소 활용의 규칙성 등에 따라 구성 형태소로의 분석을 통해 활용된 단어를 이해하거나 아니면 활용된 어휘의 직접적인 접근을 통해 활용된 단어를 이해한다는 것이다. 본 연구에서는 이 세 종류의 가설 중에 어느 가설이 옳은 것인지를 조사하기 위해, "먹은" 흑은 "쥐어"와 같은 한국어 어절을 이용하여 형태소 표상 양식과 이해 과정을 다루었다. 본 연구의 목적을 위해 점화 어휘 판단 과제(primed-lexical decision task)를 사용하였다. 실험 1은 "먹은"처럼 동사 "먹다"로도 해석이 가능하고 명사 "먹"으로도 가능한 중의적 어절을 점화 문자열로 제시하고 이 문자열이 두 의미와 관련된 목표 단어 재인에 어떤 영향을 끼치는지를 조사하였다. 만일에 "먹"이라는 어근 혹은 어간으로의 분석을 통해 이 어절을 이해한다면 두 종류의 의미와 관련된 조건 모두에서 촉진적 점화 효과(facilitatory priming effect)가 나타날 것이고, 어절 전체로의 어휘 접근 과정이 일어난다면 사용빈도에서 높은 동사 뜻과 관련된 조건에서만 촉진적 점화 효과가 나타날 것이다. 실험 1의 결과는 두 종류의 의미가 모두 활성화되는 것을 보여 주었다. 즉, "먹은"과 간은 어절 이해는 구성 형태소로의 분석과 구성 형태소 어휘 접근을 통해 어절 이해가 이루어진다는 가설을 지지하고 있다. 실험 2에서는 실험 1과 다르게 한 뜻으로만 안일 수밖에 없는 "쥐어"와 같은 어절을 사용하여 이런 경우에도(즉, 어절의 문맥이 특정 뜻으로 한정하는 경우) 구성 형태소로의 분석 과정이 일어나는지를 조사하였다. 실험 2의 결과는 실험 1의 결과와는 다르게 어간의 한가지 의미와 관련된 조건만 촉진적 점화 효과가 나타나는 것을 보여주었다. 특히, 실험 2에서 SOA가 1000msec일 경우, 두 의미의 활성화가 나타나는 것을 보여주었는데, 이 같은 결과는 어절 문맥이 특정한 의미로 한정시킬 경우는 심성어휘집에 활용형태로 들어있다는 것이다. 또한 명칭성 실어증 환자의 경우에는 즉시적 점화과제에서는 일반인과 같은 형태소 처리과정을 보였으나, 그이후의 처리과정이 일반인과 다른 형태를 보였다. 실험 1과 실험 2의 결과는 한국어 어절 분석이 구문분석 또는 활용형태를 통해 어휘 접근되는 가설을 지지하고 있다. 또 명칭성 실어증 환자의 경우에는 지연된 점화과제에서 형태소 처리가 일반인과 다르다는 것이 밝혀졌다. 이 결과가 옳다면 한국의 심성 어휘집은 어절 문맥에 따라서 어간이나 어근 또는 활용형 그 자체로 이루어져 있을 것이다.

• Korean Journal of Optics and Photonics
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• v.24 no.3
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• pp.135-142
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• 2013

Two white light emitting diodes(LEDs) were fabricated by using two kinds of yellow phosphor, YAG:Ce and $(Sr,Ba)_2SiO4:Eu$, and their spectroscopic properties were analyzed as a function of temperature from room temperature to $80^{\circ}C$. The asymmetric double sigmoidal function was applied to both blue and yellow peaks of the emitting spectrum to obtain the center wavelength, the amplitude, the half width, and the skewness parameters. According to this analysis, the center wavelength of the blue peak shifted to longer wavelength while that of the yellow peak shifted to shorter wavelength. In addition, some of the skewness parameters were found to increase upon heating, which indicates that spectrum asymmetry becomes enhanced at higher temperatures. The changes in the color coordinates and the luminous efficacy were larger for the case of silicate-based white LED. These results suggest that the silicate-based white LED is inferior to the YAG-based white LED from the viewpoint of color stability, efficacy and color rendering index.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.181-190
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• 2012

Cost of capital is one of the key factors of accounting regulation policy for telecommunication market. This paper aims at investigating efficient policy improvements concerning accounting regulation for telecommunication market focused on cost of capital calculation methods and its application. At First, cost of capital estimating method should be improved. In estimating the cost of equity capital, it is necessary to use benchmark method for Equity risk premium. It will reduce analytical errors caused by a rapid economic change and inflation. It is also more desirable to use debt premium adding method for the cost of debt capital. Optimal capital structure method may be considered a better way to estimates capital structure. Secondly, cost of capital estimating process also has to be reformed. Telecommunication industry changes rapidly so it does not reflect fast environmental changes. Therefore, cost of capital should be calculated every year. Cost of capital should be calculated by individual companies. There is information asymmetry between regulators and regulatees. Because of that cost of capital calculating process takes long time and cost a lot. To solve this problem, regulator should legislate on cost of capital calculation and then regulating companies report the calculating result. Lastly, major telecommunication companies are all listed now and it is possible to calculating it separately. We must continuously improve the estimating method and application of cost of capital and due to the fast growing of telecommunication industry. The process of determining the calculating method must be discussed and best method chosen.

• Journal of the Korean Magnetics Society
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• v.19 no.4
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• pp.121-125
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• 2009

Amorphous $Ge_1$_$_xMn_x$ semiconductor thin films grown by low temperature vapor deposition were annealed at various temperatures from 400 to $700^{\circ}C$ for 3 minutes in high vaccum chamber. The electrical and magnetotransport properties of as-grown and annealed samples have been studied. X-ray diffraction patterns analysis revealed that the samples still maintain amorphous state after annealling at $500^{\circ}C$ for 3 minutes and they were crystallized when annealing temperature increase to $600^{\circ}C$. Temperature dependence of resistivity measurement implied that as-grown and annealed $Ge_1$_$_xMn_x$ films have semiconductor characteristics, the increase of resistivity with annealling temperature was obseved. The $700^{\circ}C$-annealed sample exhibited negative magnetoresistance (MR) at low temperatures and the MR ratio was ${\sim}$8.5% at 10 K. The asymmetry was present in all MR curves. The anomalous Hall Effect was also observed at 250 K.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.149-156
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• 1993

Intramolecular excimerization of 1,3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to examine the effects of ethanol on the rate and range of lateral diffusion of bulk bilayer structures of plasma membrane vesicles isolated from cultured mouse myeloma cell line Sp2/0-Ag14 (Sp2/0-PMV). In a concentration-dependent manner, ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the Sp2/0-PMV and decreased the anisotropy (r), limiting anisotropy $(r_{\infty})$, and order parameter (S) of DPH in the Sp2/0-PMV. This indicates that ethanol increased both the lateral and rotational diffusion of the probes in the Sp2/0-PMV. Selective quenching of DPH by trinitrophenyl groups was utilized to examine the transbilayer asymmetric rotational diffusion of the Sp2/0-PMV. The anisotropy (r), limiting anisotropy $(r_{\infty})$, and order parameter (S) of DPH in the inner monolayer were 0.022, 0.029, and 0.063, respectively, greater than calculated for the outer monolayer of the Sp2/0-PMV. Selective quenching of DPH by trinitrophenyl groups was also utilized to examine the transbilayer asymmetric effects of ethanol on the range of rotational diffusion of the Sp2/0-PMV. Ethanol had a greater fluidizing effect on the outer monolayer as compared to the inner monolayer of the Sp2/0-PMV. It has been proven that ethanol exhibits a selective rather than nonselective fluidizing effect within transbilayer domains of the Sp2/0-PMV.

• The Korean Journal of Financial Management
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• v.22 no.1
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• pp.119-146
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• 2005

This study applies extreme value theory to get extreme value-VAR for Korean Stock market and showed the usefulness of the approach. Block maxima model and POT model were used as extreme value models and tested which model was more appropriate through back testing. It was shown that the block maxima model was unstable as the variation of the estimate was very large depending on the confidence level and the magnitude of the estimates depended largely on the block size. This shows that block maxima model was not appropriate for Korean Stock market. On the other hand POT model was relatively stable even though extreme value VAR depended on the selection of the critical value. Back test also showed VAR showed a better result than delta VAR above 97.5% confidence level. POT model performs better the higher the confidence level, which suggests that POT model is useful as a risk management tool especially for VAR estimates with a confidence level higher than 99%. This study picks up the right tail and left tail of the return distribution and estimates the EVT-VAR for each, which reflects the asymmetry of the return distribution of the Korean Stock market.

• The Korean Journal of Financial Management
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• v.26 no.3
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• pp.139-169
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• 2009

This paper introduces the modified VaR which takes into account the asymmetry and fat-tails of financial asset distribution, and then compares its out-of-sample forecast performance with traditional VaR model such as historical simulation model and Riskmetrics. The empirical tests using stock indices of 6 countries showed that the modified VaR has the best forecast accuracy. At the test of independence, Riskmetrics and GARCH model showed best performances, but the independence was not rejected for the modified VaR. The Monte Carlo simulation using skew t distribution again proved the best forecast performance of the modified VaR. One of many advantages of the modified VaR is that it is appropriate for measuring VaR of the portfolio, because it can reflect not only the linear relationship but also the nonlinear relationship between individual assets of the portfolio through coskewness and cokurtosis. The empirical analysis about decomposing VaR of the portfolio of 6 stock indices confirmed that the component VaR is very useful for the re-allocation of component assets to achieve higher Sharpe ratio and the active risk management.